1. Technical Field
The present invention relates to a manufacturing method for an optical information recording medium and an optical information recording medium. More particularly, the present invention relates to, for example, a manufacturing method for a multilayer optical information recording medium having a plurality of information recording layers and a plurality of intermediate layers and a multilayer optical information recording medium.
2. Background Art
In recent years, in the field of information recording, various researches on optical information recording have been conducted. Optical information recording makes it possible to achieve higher-density recording and non-contact recording/reproduction at low costs, and therefore has been applied to a wide range of applications. Currently, various optical discs such as CDs, DVDs, and Blu-ray discs are widely used.
Blu-ray discs currently used have two information recording layers and can store up to 50 GB of information. Blu-ray disc media types are categorized into read-only type, write-once type, and rewritable type. In order to achieve larger-capacity recording and higher-density, research on multilayer Blu-ray discs having three or more information recording layers is currently underway, and some multilayer Blu-ray discs have already been proposed, as shown in Japanese Patent No. 3763763 and Japanese Patent Laid-open Publication No. 2005-141816.
Such a multilayer Blu-ray disc is basically constituted from a substrate having a thickness of about 1.1 mm, a plurality of intermediate layers, a plurality of information recording layers separated from each other by the intermediate layers, and a light transmitting layer allowing light for recording/reproducing information to pass through and protecting the information recording layer. The substrate is often made of polycarbonate, and the intermediate layers and the light transmitting layer are often made of a UV curable resin.